Service manual

Types of Cache
Chapter 6 Tuning Cache Sizes 111
File System Cache
The operating system allocates available memory not used by Directory Server
caches and other applications to the file system cache. This cache holds data
recently read from the disk, making it possible for subsequent requests to obtain
data copied from cache rather than to read it again from the disk. As memory
access is many times faster than disk access, leaving some physical memory
available to the file system cache can boost performance.
Refer to the operating system documentation for details on file system cache.
Total Aggregate Cache Size
The sum of all caches used simultaneously must remain smaller than the total size
of available physical memory, less the memory intended for file system cache. For
32-bitservers,thismeanstotalaggregatecachesizemustinpracticebelimitedto2
GB or less. Total cache used may well be significantly larger than the size you specify.
Refer to “Database Cache,” onpage 108 for hints on how to check that the cache
size and thus Directory Server process size does not exceed available physical
memory.
If suffixes are initialized (bulk loaded) while Directory Server is online, the sum of
database, entry, and importcache sizes should remain smallerthan the totalsize of
available physical memory.
NOTE OnWindowsplatforms,themaximum addressspace availableto an
application is 2 GB. If the total aggregate cache size exceeds this
limit, Directory Server exits with an error message.
Table 6-2 Suffix Initialization (Import) Operations and Cache Use
Cache Type Offline Import Online Import
Database no yes
Entry yes yes
Import yes yes